Fantastic Voyages

This paper describes the use of nanotechnology in detection of disease at its earliest stage. Nanotechnology makes it possible to envision new devices that can deliver a 100-fold and even larger increase in sensitivity over current diagnostic techniques. Very small-scale diagnostic devices have been designed depending on the transduction mechanism—mechanical or electrical—of the biomedical stimulus. Devices that use nanocantilevers, nanowires, and nanoparticles have been built and tested, and are currently under development. The nanowire-based devices are nanometer-wide semiconductor wires coated with molecules arranged in parallel on the bottom of a microfluidic chamber where a blood sample is introduced for analysis. The binding event among the molecules on the wire and the biomarkers in the sample produces a change in the electrical conductivity of the wire that can be measured in real time and related to the amount of biomarkers in solution.